Historically, I've manually copied personal files onto multiple hard drives periodically to keep them backed up, but I just emptied my wallet getting certain files that were only stored in one place (because they were so large I didn't have space to duplicate them) recovered from a hard drive that failed. I'm hoping to prevent this from ever happening again.

My goal is not to run my whole operating system on a RAID - I just want a certain set of personal files on a 2TB drive to be synchronized with a second external drive. Furthermore, to take advantage of the expense of two drives storing files redundantly, I'd appreciate it if there was a way to set this up such that my system could leverage faster read/write times by sharing the load between both disks, and keeping them mirrored while i/o is idle.

Building on this system, I want to be able to have offline availability of a subset of these files (Documents, Pictures and Music, but not videos) on any of 3 home computers. If a file is changed locally on any machine, which later reconnects to the network, I'd like changes to these files to be synchronized back to the main 'server'.

I'll do my best to illustrate my goal. Pardon the MSPaint art.

I'm using windows machines primarily, so for the offline file synchronization, I wouldn't be surprised if there's a built in windows service. As for maintaining a RAID 1 using an external, though, I'm completely in the dark. I'm somewhat familiar with operating systems running on top of a RAID, but really what I want is a 2TB external drive that is mirrored with a drive built into the PC, but can still be disconnected so that I can travel with my files, and re-connect it at a later date to restore the RAID.

Perhaps a RAID format isn't the ideal solution here. Maybe just some software that constantly synchronizes files between multiple directories. A huge plus would be if I could do this while the 2TB external is formatted as a FAT32, so that I could still connect it to Gaming systems, etc.

EDIT
I think "Offline Files" will satisfy my need for remote file access from machines other than my "server", but in terms of the RAID 1 setup, is there any way I can experience read performance improvements at the same time? Seems a shame to waste 2TB and get nothing other than fault tolerance out of it.

I just realized I won't be able to set up these mirrored drives with a FAT32 file system because they don't support files >= 4GB. I might as well just format them as RAID 1 in that event. True?
–
AlainFeb 9 '11 at 15:07

2 Answers
2

I watched for years as people tried
RAID 1 to save their behinds from
failed drives. Sadly I never found it
to pay off in decades. The issues of
user error, virus, pest and worms
actually made RAID 1 a liability since
many (misinformed) owners thought it
was a backup in realtime. Yes, it was.
As soon as an error occurred it was
faithfully duplicated in the RAID 1
mirror drive.

To double the trouble the owner who
thought it was a backup discontinued
making backups offline to tape or
disks.

I'm sure there is one success story
out there but in decades I've never
encounted one.

-> If you had RAID 5 I will write I've seen that work, but they had a few
dozen drives on that system.

Maybe it's time to give up RAID 1 for
speed and occasionally backup.

In my case, I have very little fear of viral activity or user error resulting in data loss, only hardware failure. Still, it looks like I wouldn't even get a read performance enhancement out of creating a RAID 1, so perhaps my best solution is just to manually back up one 2TB external on the other once in a while?

Rsync

If "constantly synchronised" can be relaxed to "periodically synchronised" (say once an hour) you could use rsync (*nix, Windows) or one of it's derivatives like duplicity or a similar tool like unison.

I think "Offline Files" will satisfy my need for remote file access from machines other than my "server", but in terms of the RAID 1 setup, is there any way I can experience read performance improvements at the same time? Seems a shame to waste 2TB and get nothing other than fault tolerance out of it.
–
AlainFeb 9 '11 at 15:31